import java.io.*;
import java.util.Scanner;

public class Caesar {
    public static void main(String[] args){
        System.out.print("请输入密钥：");
        Scanner s = new Scanner(System.in);
        int a = s.nextInt();
        C(a);
    }


    public static void C(int n){
        try{
            char b[];
            BufferedReader br2 = new BufferedReader(new InputStreamReader(System.in));
            System.out.println("请输入一段明文：");
            String str2 = br2.readLine();
            b = str2.toCharArray();
            System.out.println("密文为：");
            int k = n;
            for(int i = 0;i < str2.length();i++){
                char ch = (char)((b[i] - 'a' +k)%26 +'a');
                System.out.print(ch);
            }
            System.out.println("密钥 K = " + k);
        }catch(IOException e){
            System.out.println(e.getMessage());
        }
    }
}